1. Field
The present invention relates to a vane pump device.
2. Description of Related Art
JP-A-2011-196302 discloses a vane pump including a switching valve that switches between a full discharge position at which a working fluid is suctioned to and discharged from both main and sub regions and a half-discharge position at which the working fluid is suctioned to and discharged from only the main region. The switching valve switches pressure introduced to vanes in the sub region such that the vanes retract into a rotor and move away from an inner circumferential cam surface of a cam ring at the half-discharge position.
A vane pump device may adopt a configuration in which vanes protrude due to a predetermined pressure of a working fluid being supplied to vane grooves supporting the vanes. In this case, the amount of the working fluid used in the vane pump device is limited, and thus, the amount of the working fluid supplied to the vane grooves preferably is small. In contrast, it is necessary to supply a certain amount of the working fluid to the vane grooves so that the vanes suitably protrude.